Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Leases
Operating lease cost	$ 14,004	$ 18,281	$ 47,585	$ 54,130
Short-term lease cost (1)	2,488	2,726	9,686	8,284
Amortization of right-of-use assets	17,829	17,829	53,488	53,488
Interest on lease liabilities	3,467	5,070	11,635	16,326
Total finance lease cost	21,296	22,899	65,123	69,814
Total lease costs	37,788	$ 43,906	122,394	$ 132,228
Operating lease assets	$ 853,140		$ 853,140		$ 104,271